1. Patent statistics as a measure of technichange;Comanor;Journal of Political Economy,1969
2. The estimation of distributed lags in short panels;Griliches;NBER Technical Working Paper no. 4,1980
3. The rate and direction of inventive activity: Economic and social factors,1962
4. Patents and R&D at the first level: A first look;Pakes;NBER Working Paper no. 561,1980
5. Firm size, market structure, opportunity, and the output of patented innovations;Scherer;American Economic Review,1965